Interplay of intracellular and trans-cellular DNA methylation in natural archaeal consortia.

DNA methylation serves a variety of functions across all life domains. In this study, we investigated archaeal methylomics within a tripartite xylanolytic halophilic consortium. This consortium includes Haloferax lucertense SVX82, Halorhabdus sp. SVX81, and an ectosymbiotic Candidatus Nanohalococcus occultus SVXNc, a nano-sized archaeon from the DPANN superphylum. We utilized PacBio SMRT and Illumina cDNA sequencing to analyse samples from consortia of different compositions for methylomics and transcriptomics. Endogenous cTAG methylation, typical of Haloferax, was accompanied in this strain by methylation at four other motifs, including GDGcHC methylation, which is specific to the ectosymbiont. Our analysis of the distribution of methylated and unmethylated motifs suggests that autochthonous cTAG methylation may influence gene regulation. The frequency of GRAGAaG methylation increased in highly expressed genes, while CcTTG and GTCGaGG methylation could be linked to restriction-modification (RM) activity. Generally, the RM activity might have been reduced during the evolution of this archaeon to balance the protection of cells from intruders, the reduction of DNA damage due to self-restriction in stressful environments, and the benefits of DNA exchange under extreme conditions. Our methylomics, transcriptomics and complementary electron cryotomography (cryo-ET) data suggest that the nanohaloarchaeon exports its methyltransferase to methylate the Haloferax genome, unveiling a new aspect of the interaction between the symbiont and its host.

Whole genome sequencing and genotyping Klebsiella pneumoniae multi-drug resistant hospital isolates from Western Kenya.

Objectives: Klebsiella pneumoniae are a frequent cause of nosocomial infections worldwide. Sequence type 147 (ST147) has been reported as a major circulating high-risk lineage in many countries, and appears to be a formidable platform for the dissemination of antimicrobial resistance (AMR) determinants. However, the distribution of this pathogen in Western African hospitals has been scarcely studied. The main objective of this work was to perform whole genome sequencing of K. pneumoniae isolates from a referral hospital in Kakamega (Kenya) for genotyping and identification of AMR and virulence determinants. Methods: In total, 15 K. pneumoniae isolates showing a broad spectrum antimicrobial resistance were selected for whole genome sequencing by Illumina HiSeq 2500 platform. Results: ST147 was the dominant lineage among the highly-resistant K. pneumoniae isolates that we sequenced. ST147 was associated with both community- and the hospital-acquired infections, and with different infection sites, whereas other STs were predominantly uropathogens. Multiple antibiotic resistance and virulence determinants were detected in the genomes including extended-spectrum ß-lactamases (ESBL) and carbapenemases. Many of these genes were plasmid-borne. Conclusions: Our data suggest that the evolutionary success of ST147 may be linked with the acquisition of broad host-range plasmids, and their propensity to accrue AMR and virulence determinants. Although ST147 is a dominant lineage in many countries worldwide, it has not been previously reported as prevalent in Africa. Our data suggest an influx of new nosocomial pathogens with new virulence genes into African hospitals from other continents.

The Effect of Three Complexes of Iodine with Amino Acids on Gene Expression of Model Antibiotic Resistant Microorganisms Escherichia coli ATCC BAA-196 and Staphylococcus aureus ATCC BAA-39.

1. BACKGROUND: Iodine is a broad-spectrum antimicrobial disinfectant for topical application. Recent studies have shown promising results on the applicability of an iodine-containing complex, FS-1, against antibiotic-resistant pathogens. It was hypothesized that the antimicrobial activity of iodine-containing complexes may be modulated by the organic moiety of the complex, i.e., amino acids. 2. METHODS: Gene regulation and metabolic alterations were studied in two model multidrug-resistant microorganisms, Staphylococcus aureus ATCC BAA-39, and Escherichia coli ATCC BAA-196, treated with three complexes containing iodine and three different amino acids: glycine, L-alanine, and L-isoleucine. The bacterial cultures were exposed to sub-lethal concentrations of the complexes in the lagging and logarithmic growth phases. Gene regulation was studied by total RNA sequencing and differential gene expression analysis. 3. RESULTS: The central metabolism of the treated bacteria was affected. An analysis of the regulation of genes involved in stress responses suggested the disruption of cell wall integrity, DNA damage, and oxidative stress in the treated bacteria. 4. CONCLUSIONS: Previous studies showed that the application of iodine-containing complexes, such as FS-1, serves as a supplement to common antibiotics and can be a promising way to combat antibiotic-resistant pathogens. Current results shed light on possible mechanisms of this action by disrupting the cell wall barriers and imposing oxidative stress. It was also found that the effect of the complexes on metabolic pathways varied in the tested microorganisms depending on the organic moiety of the complexes and the growth phase when the complexes had been applied.

Analysis of Whole-Genome Sequences of Pathogenic Gram-Positive and Gram-Negative Isolates from the Same Hospital Environment to Investigate Common Evolutionary Trends Associated with Horizontal Gene Exchange, Mutations and DNA Methylation Patterning.

Hospital-acquired infections are a generally recognized problem for healthcare professionals. Clinical variants of Gram-negative and Gram-positive pathogens are characterized with enhanced antibiotic resistance and virulence due to mutations and the horizontal acquisition of respective genetic determinants. In this study, two Escherichia coli, two Klebsiella pneumoniae, three Pseudomonas aeruginosa, two Staphylococcus aureus, one Staphylococcus epidermidis and one Streptococcus pneumoniae showing broad spectra of antibiotic resistance were isolated from patients suffering from nosocomial infections in a local hospital in Almaty, Kazakhstan. The aim of the study was to compare general and species-specific pathways of the development of virulence and antibiotic resistance through opportunistic pathogens causing hospital-acquired infections. The whole-genome PacBio sequencing of the isolates allowed for the genotyping and identification of antibiotic resistance and virulence genetic determinants located in the chromosomes, plasmids and genomic islands. It was concluded that long-read sequencing is a useful tool for monitoring the epidemiological situation in hospitals. Marker antibiotic resistance mutations common for different microorganisms were identified, which were acquired due to antibiotic-selective pressure in the same clinical environment. The genotyping and identification of strain-specific DNA methylation motifs were found to be promising in estimating the risks associated with hospital infection outbreaks and monitoring the distribution and evolution of nosocomial pathogens.

Complete Genome Sequences of Gram-Positive Opportunistic Pathogens Isolated from Hospitals in Almaty, Kazakhstan.

The appearance of drug-resistant pathogens reduces the therapeutic applicability of antibiotics and increases the rate of hospital infections among patients. Complete genome sequences of four Gram-positive clinical isolates of Streptococcus and Staphylococcus were obtained and analyzed to serve as model microorganisms for further studies on drug-induced antibiotic resistance reversion.

Complete Genome Sequences of Gram-Negative Opportunistic Pathogens Isolated in Hospitals in Almaty, Kazakhstan.

The problem of nosocomial infections is growing due to the introduction of new treatment regimens involving immunosuppressive drugs. The genomes of seven Gram-negative clinical isolates of Escherichia, Klebsiella, and Pseudomonas were sequenced and analyzed in this study to serve as model microorganisms to study drug-induced antibiotic resistance reversion.

Transcriptomics and methylomics study on the effect of iodine-containing drug FS-1 on Escherichia coli ATCC BAA-196.

Aim: Promising results on application of iodine-containing nano-micelles, FS-1, against antibiotic-resistant Escherichia coli was demonstrated. Materials & methods: RNA sequencing for transcriptomics and the complete genome sequencing by SMRT PacBio were followed by genome assembly and methylomics. Results & conclusion: FS-1-treated E. coli showed an increased susceptibility to antibiotics ampicillin and gentamicin. Cultivation with FS-1 caused gene expression alterations toward anaerobic respiration, increased anabolism and inhibition of many nutrient uptake systems. Main targets of iodine-containing particles were cell membrane structures causing oxidative, osmotic and acidic stresses. Identification of methylated nucleotides showed an altered pattern in the FS-1-treated culture. Possible role of transcriptional and epigenetic modifications in the observed increase in susceptibility to gentamicin and ampicillin were discussed.

Lay abstract New approaches of combatting drug-resistant infections are in demand as the development of new antibiotics is in a deep crisis. This study was set out to investigate molecular mechanisms of action of new iodine-containing nano-micelle drug FS-1, which potentially may improve the antibiotic therapy of drug-resistant infections. Iodine is one of the oldest antimicrobials and until now there were no reports on development of resistance to iodine. Recent studies showed promising results on application of iodine-containing nano-micelles against antibiotic-resistant pathogens as a supplement to antibiotic therapy. The mechanisms of action, however, remain unclear. The collection strain Escherichia coli ATCC BAA-196 showing an extended spectrum of resistance to ßß-lactam and aminoglycoside antibiotics was used in this study as a model organism. Antibiotic resistance patterns, whole genomes and total RNA sequences of the FS-1-treated (FS) and negative control (NC) variants of E. coli BAA-196 were obtained and analyzed. FS culture showed an increased susceptibility to antibiotics associated with profound gene expression alterations switching the bacterial metabolism to anaerobic respiration, increased anabolism, osmotic stress response and inhibition of many nutrient uptake systems. Nucleotide methylation pattern were identified in FS and NC cultures. While the numbers of methylated sites in both genomes remained similar, some peculiar alterations were observed in their distribution along chromosomal and plasmid sequences.

The Epistatic Landscape of Antibiotic Resistance of Different Clades of Mycobacterium tuberculosis.

Drug resistance (DR) remains a global challenge in tuberculosis (TB) control. In order to develop molecular-based diagnostic methods to replace the traditional culture-based diagnostics, there is a need for a thorough understanding of the processes that govern TB drug resistance. The use of whole-genome sequencing coupled with statistical and computational methods has shown great potential in unraveling the complexity of the evolution of DR-TB. In this study, we took an innovative approach that sought to determine nonrandom associations between polymorphic sites in Mycobacterium tuberculosis (Mtb) genomes. Attributable risk statistics were applied to identify the epistatic determinants of DR in different clades of Mtb and the possible evolutionary pathways of DR development. It was found that different lineages of Mtb exploited different evolutionary trajectories towards multidrug resistance and compensatory evolution to reduce the DR-associated fitness cost. Epistasis of DR acquisition is a new area of research that will aid in the better understanding of evolutionary biological processes and allow predicting upcoming multidrug-resistant pathogens before a new outbreak strikes humanity.

Whole Genome-Based Characterization of Listeria monocytogenes Isolates Recovered From the Food Chain in South Africa.

Listeria monocytogenes is an important foodborne pathogen which has the ability to adapt and survive in food and food processing facilities where it can persist for years. In this study, a total of 143 L. monocytogenes isolates in South Africa (SA) were characterized for their strain's genetic relatedness, virulence profiles, stress tolerance and resistance genes associated with L. monocytogenes. The Core Genome Multilocus Sequence Typing (cgMLST) analysis revealed that the most frequent serogroups were IVb and IIa; Sequence Types (ST) were ST204, ST2, and ST1; and Clonal Complexes (CC) were CC204, CC1, and CC2. Examination of genes involved in adaptation and survival of L. monocytogenes in SA showed that ST1, ST2, ST121, ST204, and ST321 are well adapted in food processing environments due to the significant over-representation of Benzalkonium chloride (BC) resistance genes (bcrABC cassette, ermC, mdrL and Ide), stress tolerance genes (SSI-1 and SSI-2), Prophage (φ) profiles (LP_101, vB LmoS 188, vB_LmoS_293, and B054 phage), plasmids profiles (N1-011A, J1776, and pLM5578) and biofilm formation associated genes. Furthermore, the L. monocytogenes strains that showed hyper-virulent potential were ST1, ST2 and ST204, and hypo-virulent were ST121 and ST321 because of the presence and absence of major virulence factors such as LIPI-1, LIPI-3, LIPI-4 and the internalin gene family members including inlABCEFJ. The information provided in this study revealed that hyper-virulent strains ST1, ST2, and ST204 could present a major public health risk due to their association with meat products and food processing environments in SA.

Comparison of Transcriptional Responses and Metabolic Alterations in Three Multidrug-Resistant Model Microorganisms, Staphylococcus aureus ATCC BAA-39, Escherichia coli ATCC BAA-196, and Acinetobacter baumannii ATCC BAA-1790, on Exposure to Iodine-Containing Nano-micelle Drug FS-1.

Iodine is one of the oldest antimicrobial agents. Until now, there have been no reports on acquiring resistance to iodine. Recent studies showed promising results on application of iodine-containing nano-micelles, FS-1, against antibiotic-resistant pathogens as a supplement to antibiotic therapy. The mechanisms of the action, however, remain unclear. The aim of this study was to perform a holistic analysis and comparison of gene regulation in three phylogenetically distant multidrug-resistant reference strains representing pathogens associated with nosocomial infections from the ATCC culture collection: Escherichia coli BAA-196, Staphylococcus aureus BAA-39, and Acinetobacter baumannii BAA-1790. These cultures were treated by a 5-min exposure to sublethal concentrations of the iodine-containing drug FS-1 applied in the late lagging phase and the middle of the logarithmic growth phase. Complete genome sequences of these strains were obtained in the previous studies. Gene regulation was studied by total RNA extraction and Ion Torrent sequencing followed by mapping the RNA reads against the reference genome sequences and statistical processing of read counts using the DESeq2 algorithm. It was found that the treatment of bacteria with FS-1 profoundly affected the expression of many genes involved in the central metabolic pathways; however, alterations of the gene expression profiles were species specific and depended on the growth phase. Disruption of respiratory electron transfer membrane complexes, increased penetrability of bacterial cell walls, and osmotic and oxidative stresses leading to DNA damage were the major factors influencing the treated bacteria.IMPORTANCE Infections caused by antibiotic-resistant bacteria threaten public health worldwide. Combinatorial therapy in which antibiotics are administered together with supplementary drugs improving susceptibility of pathogens to the regular antibiotics is considered a promising way to overcome this problem. An induction of antibiotic resistance reversion by the iodine-containing nano-micelle drug FS-1 has been reported recently. This drug is currently under clinical trials in Kazakhstan against multidrug-resistant tuberculosis. The effects of released iodine on metabolic and regulatory processes in bacterial cells remain unexplored. The current work provides an insight into gene regulation in the antibiotic-resistant nosocomial reference strains treated with iodine-containing nanoparticles. This study sheds light on unexplored bioactivities of iodine and the mechanisms of its antibacterial effect when applied in sublethal concentrations. This knowledge will aid in the future design of new drugs against antibiotic-resistant infections.

Virulence and antimicrobial resistance genes are enriched in the plasmidome of clinical Escherichia coli isolates compared with wastewater isolates from western Kenya.

Many low-middle income countries in Africa have poorly-developed infectious disease monitoring systems. Here, we employed whole genome sequencing (WGS) to investigate the presence/absence of antimicrobial resistance (AMR) and virulence-associated (VA) genes in a collection of clinical and municipal wastewater Escherichia coli isolates from Kakamega, west Kenya. We were particularly interested to see whether, given the association between infection and water quality, the isolates from these geographically-linked environments might display similar genomic signatures. Phylogenetic analysis based on the core genes common to all of the isolates revealed two broad divisions, corresponding to the commensal/enterotoxigenic E. coli on the one hand, and uropathogenic E. coli on the other. Although the clinical and wastewater isolates each contained a very similar mean number of antibiotic resistance-encoding genes, the clinical isolates were enriched in genes required for in-host survival. Furthermore, and although the chromosomally encoded repertoire of these genes was similar in all sequenced isolates, the genetic composition of the plasmids from clinical and wastewater E. coli was more habitat-specific, with the clinical isolate plasmidome enriched in AMR and VA genes. Intriguingly, the plasmid-borne VA genes were often duplicates of genes already present on the chromosome, whereas the plasmid-borne AMR determinants were more specific. This reinforces the notion that plasmids are a primary means by which infection-related AMR and VA-associated genes are acquired and disseminated among these strains.

The Effect of Iodine-Containing Nano-Micelles, FS-1, on Antibiotic Resistance, Gene Expression and Epigenetic Modifications in the Genome of Multidrug Resistant MRSA Strain Staphylococcus aureus ATCC BAA-39.

Application of supplementary drugs which increase susceptibility of pathogenic bacteria to antibiotics is a promising yet unexplored approach to overcome the global problem of multidrug-resistant infections. The discovery of a new drug, an iodine-containing nano-molecular complex FS-1, which has proven to improve susceptibility to antibiotics in various pathogens, including MRSA strain Staphylococcus aureus ATCC BAA-39TM, allowed studying this phenomenon. Chromosomal DNA and total RNA samples extracted from the FS-1 treated strain (FS) and from the negative control (NC) cultures were sequenced by PacBio SMRT and Ion Torrent technologies, respectively. PacBio DNA reads were used to assemble chromosomal DNA of the NC and FS variants of S. aureus BAA-39 and to perform profiling of epigenetically modified nucleotides. Results of transcriptional profiling, variant calling and detection of epigenetic modifications in the FS variant were compared to the NC variant. Additionally, the genetic alterations caused by the treatment of S. aureus BAA-39 with FS-1 were compared to the results of a similar experiment conducted with another model organism, E. coli ATCC BAA-196. Several commonalities in responses of these phylogenetically distant microorganisms to the treatment with FS-1 were discovered, which included metabolic transition toward anaerobiosis and oxidative/osmotic stress response. S. aureus culture appeared to be more sensitive to FS-1 due to a higher penetrability of cells by iodine bound compounds, which caused carbonyl stress associated with nucleotide damaging by FS-1, abnormal epigenetic modifications and an increased rate of mutations. It was hypothesized that the disrupted pattern of adenine methylated loci within methicillin-resistance chromosome cassettes (SCCmec) may promote excision of this antibiotic resistance determinant from chromosomes while the altered pattern of cytosine methylation was behind the adaptive gene regulation in the culture FS. The selection against the antibiotic resistance in bacterial populations caused by abnormal epigenetic modifications exemplifies possible mechanisms of antibiotic resistance reversion induced by iodine-containing compounds. These finding will facilitate development of therapeutic agents against multidrug-resistant infections.

Complete genome sequence and epigenetic profile of Bacillus velezensis UCMB5140 used for plant and crop protection in comparison with other plant-associated Bacillus strains.

The application of biocontrol biopesticides based on plant growth-promoting rhizobacteria (PGPR), particularly members of the genus Bacillus, is considered a promising perspective to make agricultural practices sustainable and ecologically safe. Recent advances in genome sequencing by third-generation sequencing technologies, e.g., Pacific Biosciences' Single Molecule Real-Time (PacBio SMRT) platform, have allowed researchers to gain deeper insights into the molecular and genetic mechanisms of PGPR activities, and to compare whole genome sequences and global patterns of epigenetic modifications. In the current work, this approach was used to sequence and compare four Bacillus strains that exhibited various PGPR activities including the strain UCMB5140, which is used in the commercial biopesticide Phytosubtil. Whole genome comparison and phylogenomic inference assigned the strain UCMB5140 to the species Bacillus velezensis. Strong biocontrol activities of this strain were confirmed in several bioassays. Several factors that affect the evolution of active PGPR B. velezensis strains were identified: (1) horizontal acquisition of novel non-ribosomal peptide synthetases (NRPS) and adhesion genes; (2) rearrangements of functional modules of NRPS genes leading to strain specific combinations of their encoded products; (3) gain and loss of methyltransferases that can cause global alterations in DNA methylation patterns, which eventually may affect gene expression and regulate transcription. Notably, we identified a horizontally transferred NRPS operon encoding an uncharacterized polypeptide antibiotic in B. velezensis UCMB5140. Other horizontally acquired genes comprised a possible adhesin and a methyltransferase, which may explain the strain-specific methylation pattern of the chromosomal DNA of UCMB5140. KEY POINTS: • Whole genome sequence of the active PGPR Bacillus velezensis UCMB5140. • Identification of genetic determinants responsible for PGPR activities. • Role of methyltransferases and epigenetic mechanisms in evolution of bacteria.

Complete Genome Sequence of Collection Strain Acinetobacter baumannii ATCC BAA-1790, Used as a Model To Study the Antibiotic Resistance Reversion Induced by Iodine-Containing Complexes.

The strain Acinetobacter baumannii ATCC BAA-1790 was sequenced as a model for nosocomial multidrug-resistant infections. Long-read PacBio sequencing revealed a circular chromosome of 3,963,235 bp with two horizontally transferred genomic islands and a 67,023-bp plasmid. Multiple antibiotic resistance genes and genome methylation patterns were identified.

Resistance Sniffer: An online tool for prediction of drug resistance patterns of Mycobacterium tuberculosis isolates using next generation sequencing data.

The effective control of multidrug resistant tuberculosis (MDR-TB) relies upon the timely diagnosis and correct treatment of all tuberculosis cases. Whole genome sequencing (WGS) has great potential as a method for the rapid diagnosis of drug resistant Mycobacterium tuberculosis (Mtb) isolates. This method overcomes most of the problems that are associated with current phenotypic drug susceptibility testing. However, the application of WGS in the clinical setting has been deterred by data complexities and skill requirements for implementing the technologies as well as clinical interpretation of the next generation sequencing (NGS) data. The proposed diagnostic application was drawn upon recent discoveries of patterns of Mtb clade-specific genetic polymorphisms associated with antibiotic resistance. A catalogue of genetic determinants of resistance to thirteen anti-TB drugs for each phylogenetic clade was created. A computational algorithm for the identification of states of diagnostic polymorphisms was implemented as an online software tool, Resistance Sniffer (http://resistance-sniffer.bi.up.ac.za/), and as a stand-alone software tool to predict drug resistance in Mtb isolates using complete or partial genome datasets in different file formats including raw Illumina fastq read files. The program was validated on sequenced Mtb isolates with data on antibiotic resistance trials available from GMTV database and from the TB Platform of South African Medical Research Council (SAMRC), Pretoria. The program proved to be suitable for probabilistic prediction of drug resistance profiles of individual strains and large sequence data sets.

Genetic, Epigenetic and Phenotypic Diversity of Four Bacillus velezensis Strains Used for Plant Protection or as Probiotics.

Bacillus velezensis strains are applied as ecologically safe biopesticides, plant growth promoting rhizobacteria (PGPR), and in veterinary probiotics. They are abundant in various environments including soil, plants, marine habitats, the intestinal micro-flora, etc. The mechanisms underlying this adaptive plasticity and bioactivity are not well understood, nor is it clear why several strains outperform other same species isolates by their bioactivities. The main objective of this work was to demonstrate versatility of bioactivities and lifestyle strategies of the selected B. velezensis strains suitable to serve as model organisms in future studies. Here, we performed a comparative study of newly sequenced genomes of four B. velezensis isolates with distinct phenotypes and isolation origin, which were assessed by RNA sequencing under the effect of root exudate stimuli and profiled by epigenetic modifications of chromosomal DNA. Among the selected strains, UCMB5044 is an oligotrophic PGPR strain adapted to nutrient poor desert soils. UCMB5113 and At1 are endophytes that colonize plants and require nutrient rich media. In contrast, the probiotic strain, UCMB5007, is a copiotroph, which shows no propensity to colonize plants. PacBio and Illumina sequencing approaches were used to generate complete genome assemblies, tracing epigenetic modifications, and determine gene expression profiles. All sequence data was deposited at NCBI. The strains, UCMB5113 and At1, show 99% sequence identity and similar phenotypes despite being isolated from geographically distant regions. UCMB5007 and UCMB5044 represent another group of organisms with almost identical genomes but dissimilar phenotypes and plant colonization propensity. The two plant associated strains, UCMB5044 and UCMB5113, share 398 genes putatively associated with root colonization, which are activated by exposure to maize root exudates. In contrast, UCMB5007 did not respond to root exudate stimuli. It was hypothesized that alterations in the global methylation pattern and some other epigenetic modifications enable adaptation of strains to different habitats and therefore may be of importance in terms of the biotechnological applicability of these bacteria. Contrary, the ability to grow on root exudates as a sole source of nutrients or a strong antagonism against phytopathogens showed by the strains in vitro cannot be considered as good predictors of PGPR activities.

Complete Genome Sequence of a Multidrug-Resistant Strain, Escherichia coli ATCC BAA-196, as a Model for Studying Induced Antibiotic Resistance Reversion.

Here, we report the complete genome sequence of the multidrug-resistant Escherichia coli strain ATCC BAA-196, a model organism used for studying possible antibiotic resistance reversion induced by FS-1, an iodine-containing complex. Two genomes, representing FS-1-treated and negative-control variants and composed of a chromosome and several plasmids, were assembled.

Assembly of Complete Genome Sequences of Negative-Control and Experimental Strain Variants of Staphylococcus aureus ATCC BAA-39 Selected under the Effect of the Drug FS-1, Which Induces Antibiotic Resistance Reversion.

Staphylococcus aureus ATCC BAA-39 is the reference organism for a multidrug-resistant Staphylococcus aureus (MRSA) strain that was used to study drug-induced resistance reversion by an iodine-containing nanomolecular complex, FS-1. PacBio sequencing was performed on both the experimental and control strains, followed by genome assembly, variant calling, and DNA modification profiling.

Comparison of structures and cytotoxicity of mupirocin and batumin against melanoma and several other cancer cell lines.

Aim: To determine the computer-predicted anticancer activity of mupirocin and to compare its activities with those determined for another polyene antibiotic, batumin. Materials & methods: Molecular docking, cytotoxicity assays, cell microscopy and cell cycle progression were studied in cancer and nontumorigenic cell lines. Results & conclusion: Cytotoxicity of mupirocin against several cancerous cell lines was detected with the highest one (IC50 = 5.4 µg/ml) against melanoma cell line. The profile of cytotoxicity of mupirocin was similar to that reported for batumin. Nevertheless, the morphology of cells treated with these antibiotics and alterations in cell cycle progression suggested possible dissimilarity in their mechanisms of action. Selective cytotoxicity of mupirocin against melanoma cells potentiates further studies to discover nontoxic drugs for melanoma prevention.